The present disclosure relates to polymeric compositions that include cross-linkable polycarbonate resins containing a photoactive group derived from a benzophenone and bromine. Upon exposure to ultraviolet radiation, the cross-linkable polycarbonate resin will crosslink with itself and/or with other polymeric base resins also present, improving overall chemical resistance, flame retardance, and other characteristics of articles formed from the polymeric compositions. Also included are articles (e.g., sheets, films, molded components, etc.) formed from such compositions.
Polycarbonates (PC) are synthetic thermoplastic resins with desirable properties such as high impact strength and toughness, heat resistance, weather and ozone resistance, and good ductility. However, such polymers drip when exposed to a flame, and this behavior worsens as the wall thickness decreases. This behavior greatly diminishes their use in transparent and opaque thin-wall applications where a V0 or 5VA flame retardance rating is required, requiring higher loadings of flame retardance agents. Non-brominated and non-chlorinated flame retardants have been used to improve flame retardance performance, but this improvement is not robust; individual samples perform well, but good flame performance cannot be statistically predicted for multiple samples. It would be desirable to provide articles and polymeric compositions that can perform consistently and pass applicable flame retardance tests and standards.